build:opentitan: Specify host unit tests to use gcc-11 and g++-11
build:opentitan: Specify host unit tests to use gcc-11 and g++-11

binaries failed to be built with gcc/g++ 12

Change-Id: I101707449b3bdcf0f08af1c0a1e0fad099f6ddec
GitOrigin-RevId: a90fdd0453e8039ddd21bab92c73103478773123

AmbiML/sparrow-build